It has been common to fashion the sides of the outer surface of electrical extension cord receptacles with flat, vertical surfaces in order to minimize the fabrication cost of such receptacles. Such a shape not only minimizes the amount of plastic used in the molding process, but also avoids the necessity of "side cores" which must be withdrawn from the mold sideways before the molded part can be ejected from the mold. The added tooling necessary for such side cores would add significantly to the cost of the mold. The difficulty with such flat sides to the extension cord receptacle is the high degree of difficulty in removing an electrical plug from the extension cord receptacle. Since the fingers have little or no "purchase" on the sides of the receptacle, a great deal of finger strength is required to hold the receptacle while a plug is being removed. Moreover, when removing an electric plug from a prior art receptacle, there is a tendency to increase purchase on the receptacle body by inserting one's fingers into the widening gap under the plug as the plug is withdrawn. Since the electrical contacts in the plug are "live" until the plug is fully withdrawn, contact with such exposed contacts can result in dangerous shocks. The danger of such shocks is increased by the tendency to rock one's fingers into the opening while working the contact power blades loose from the receptacle contacts.
It has also become a requirement for all multi-outlet, non-grounded extension cord outlets to provide a cover to block all of the unused outlets on the receptacle. The prior art has typically provided an integrally molded long strip of plastic at the end of the receptacle which can be folded back and locked into position over either one or two outlets on the same side of the receptacle. Plastic plugs on the plastic strip must be aligned with one or the other set of electrical receptacle openings to lock the strip into position. Such long flaps require alignment of the plastic plugs with the receptacle openings to permit their use and hence are sometimes ignored when alignment is difficult. Furthermore, the double flap can only be used to cover electrical receptacle outlets on one side of the extension cord receptacle, leaving outlets on the other side uncovered if plugs are inserted only into the outlets on the one side.